Clonal fidelity of chrysanthemum regenerated from long term cultures

Morphological characteristics of flowers of long term regenerated chrysanthemum, cv. "White Spider", after ten years of micropropagation are investigated. Shoot cultures are established and maintained more than ten years by stem segment culture on MS medium supplemented with BAP and NAA (1.0, 0.1 mgL-1, respectively). Rooting of shoots (100 %) has done on MS medium without hormones and it was very successful after ten years, as well as, after two or eight years of micropropagation. Acclimation of rooted chrysanthemum plantlets at greenhouse conditions was excellent and after appropriate photoperiod "in vitro" plants flowered 90.3 % and have the same flower color, shape and size as mother plants. Flower color changes of "in vitro" plants are observed during another flowering cycle one year after acclimatization. Observed variations of chrysanthemum flowers could be attributed to epigenetic factors. Pracene su morfoloske karakteristike cvetova regeneranata cv. "White Spider" posle deset godina gajenja u kulturi in vitro. Izdanci su umnozavani u kulturi segmenata stabla preko aksilarnih pupoljaka na MS podlozi sa ?-naftilsircetnom kiselinom i benzilaminopurinom (0,5 odnosno 1,0 mgL-1), . Praceno je umnozavanje izdanaka u periodu od devetnaest pasaza (tri godine) kada je doslo do sukcesivnog smanjenja indeksa umnozavanja. Ozivljavanje izdanaka je praceno na MS podlozi bez hormona i bilo je podjednako uspesno posle dve, kao i posle osam i deset godina mikropropagacije. Ozivljene biljke hrizantema su uspesno aklimatizovane na uslove staklenika (97 %). Nakon odgovarajuceg fotoperioda, 90,3 % biljaka je cvetalo i imale su identicnu boju cveta maticnim biljkama hrizantema. Promene u boji cveta su uocene kod "in vitro" biljaka u sledecem ciklusu cvetanja, tj. godinu dana posle aklimatizacije. Ove promene bi se mogle pripisati epigenetskim faktorima.